"user A AND/OR user B" — emails can have two different From addresses? Or where does the and come in?
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Daniel Beck♦Apr 14 '11 at 15:53

What word does the / between and/or represent? I realize this is grammatical semantics, but really you are searching for A Or B which is functionally equivalent to: Only A, Only B, A And B. Vernacular does not really have a place for an exclusive OR.
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ThomasApr 14 '11 at 16:25